1. Field
The present disclosure relates to an electrode assembly and a secondary battery including the same, and more particularly, to an electrode assembly with improved energy density and flexibility regarding shapes of a battery and a secondary battery including the same.
2. Description of the Related Art
Unlike a primary battery, a secondary battery is a battery that may be charged and discharged and is widely used in the latest electronic devices, e.g., cellular phones, laptop computers, and camcorders.
Particularly, a lithium secondary battery features higher voltage and higher energy density per unit weight as compared to a nickel-cadmium battery and a nickel-hydride battery. These batteries are widely used as power sources for portable electronic devices, and demands for lithium secondary batteries are increasing.
Such a lithium secondary battery uses a lithium oxide as a positive electrode active material and a carbon-based material as a negative electrode material. Generally, lithium secondary batteries are categorized as liquid electrolyte batteries and polymer electrolyte batteries, based on the type of electrolyte. A battery using a liquid electrolyte is referred to as a lithium ion battery, whereas a battery using a polymer electrolyte is referred to as a lithium polymer battery. Furthermore, lithium secondary batteries are being manufactured in various configurations, the most popular of which are cylindrical can, prismatic can, and pouch configurations.
Generally, a jelly-roll type electrode assembly, which is formed by inserting a separator between a positive electrode plate and a negative electrode plate and winding the structure in a spiral shape, or a stacked electrode assembly, which is formed by stacking a plurality of positive electrode plates and a plurality of negative electrode plates by interposing a separator therebetween, is widely used in a lithium secondary battery. For example, a cylindrical battery is manufactured by accommodating a cylindrical jelly-roll type electrode assembly in a cylindrical can, injecting an electrolyte into the cylindrical can, and sealing the cylindrical can, whereas a prismatic battery is manufactured by press-deforming the jelly-roll type electrode assembly or a stacked electrode assembly to a prismatic shape and accommodating the deformed prismatic jelly-roll type electrode assembly in a prismatic can. Furthermore, a pouch-type battery is manufactured by packaging a jelly-roll type electrode assembly or a stacked electrode assembly and electrolyte with a pouch-type housing. In such an electrode assembly, a positive electrode tab and a negative electrode tab may be led out to an outside from a positive electrode plate and a negative electrode plate and may be connected to a positive electrode terminal and a negative electrode terminal of a secondary battery, respectively. Nonetheless, there remains a need for other configurations.